1. Technical Field
Various embodiments relate generally to an electronic device and a method of manufacturing the same and, more particularly, to a semiconductor device including three-dimensionally stacked memory cells and a method manufacturing the same.
2. Related Art
A non-volatile memory device preserves the stored data even when the power is cut off. Two-dimensional memory devices in which memory cells are fabricated in a single layer over a silicon substrate have reached physical limits in increasing their degree of integration. Accordingly, three-dimensional (3D) non-volatile memory devices in which memory cells are stacked in a vertical direction over a silicon substrate have been proposed.
A conventional 3D non-volatile memory device includes a plurality of word lines that are stacked on top of one another. Therefore, in order to select a desired one of the stacked word lines, a plurality of contact plugs may be formed so that each of the contact plugs may be coupled to each of the word lines. To this end, conventionally, the stacked word lines may be patterned into a stepped shape, and subsequently, the plurality of contact plugs may be formed. However, it may be difficult to pattern word lines into a stepped shape, and the number of processes may increase as the number of stacked word lines increases.
The conventional 3D non-volatile memory device may include global word lines and local word lines in order to apply a voltage to the stacked word lines and pass transistors in order to apply a voltage to the desired word line. However, since the pass transistors are formed over a substrate, a separate area for these pass transistors needs to be provided. Therefore, the memory device may be limited in increasing its integration degree.